1. Field of Invention
The present invention relates to a method for testing the flexible printed circuit(FPC) bonding yield and an FPC structure, and more particularly, to a method for testing the bonding yield between an FPC and a display, and an FPC having testing pads thereon.
2. Description of Related Art
The panel display is generally connected to an external system after the manufacturing process is completed, so as to supply an electric power and drive the panel display. The method commonly used for connecting the panel display to the external system presses the FPC onto an edge portion of the panel display, so that the circuit of the panel display is electrically connected to the circuit of the FPC. Since the other end of the FPC is connected to an external system, the panel display is connected to the external system via the connection provided by the FPC. However, since the FPC is weak and can be damaged by external forces, the reliability for the bonding between the FPC and the panel display is rather weak. Therefore, a bonding yield test should inevitably be performed after the FPC is bonded to the panel display.
The method for testing the bonding yield between the FPC and the panel display used in the prior art employs an optical microscope to check the bonding status of the FPC, or tests a bonding strength of the FPC by performing a pull force testing after the FPC is bonded. However, the conventional measuring method cannot measure the electrical property of the bonding for determining whether the panel display can work properly or not.
In the conventional method for measuring the electrical property of the bonding for determining whether the panel display can work properly or not, a light on process is commonly performed after the FPC is bonded to the panel display, so that it is ensured that the FPC is successfully bonded to the panel display. However, there is a problem existing in the method mentioned above for ensuring that the FPC is successfully bonded to the panel display, that is in the case where an abnormal image appears on the panel display and it is not sure whether it is caused by a bonding defect occurring between the FPC and the display or caused by a malfunction of a component inside the panel display. It is very complicated and hard to find the root cause of the abnormal image.